1. Technical Field
The present invention relates generally to apparatus and methods for moving a load from one location to another; and, more particularly, to apparatus for use aboard watercraft to: (i) raise a load, such as a small boat or dinghy; (ii) move the load to a new selected location; and (iii), lower the load at the new selected location.
2. Background Art
It is commonly known that various types of devices such as cranes and derricks are available for lifting heavy loads and transferring these loads to other locations where the loads may be deposited. Typically, these cranes are large heavy devices, often machine powered, which require large areas in which to operate and which are cumbersome to move to different job locations.
In the shipping industry, larger ships are equipped with cranes to load and off-load cargo. Smaller ships and boats not equipped with these cranes, must depend upon dock mounted cranes to accomplish heavy loading and unloading operations. Often, however, these dock mounted cranes are unavailable, particularly at smaller moorages, so that the heavy loading and unloading must be done manually.
A number of boats, however, utilize a crane-like device called a davit to raise and lower a dinghy or lifeboat between the boat and the water. The davits usually are two curved upright members which project over the side of the boat for suspending the dinghy over the water, and which allow the dinghy to be hoisted into and out of the water. The davits are typically immobile except for downwardly extending cables which are retracted and extended to raise and lower the dinghy. These davits are typically immobile except for downwardly extending cables which are retracted and extended to raise and lower the dinghy. These davits are sometimes found on some larger pleasure power boats, typically extending over the stern of the boats. Normally when a dinghy is supported by davits, the davit arms extend over the side a short distance so that the dinghy may clear the side of the boat when being raised or lowered. However, often two people are necessary to operate such devices since one person is required to operate the mechanism for raising and lowering the dinghy, while a second person must stabilize the dinghy from impacting the side of the boat during gusty winds or if the raising/lowering of the dinghy imparts a sideways motion to the dinghy.
Some power boats typically support the dinghy on a transom extending rearwardly from the stern near the water line in a manner that the dinghy is hoisted by pulling a line attached to a gunwhale of the dinghy so the dinghy may be pulled upwardly on its side to rest athwartships on the transom.
In pleasure sailing vessels, the dinghy normally is towed behind the vessel. It is undesirable to support the dinghy at the stern of the sailing vessel because the weight of the dinghy adversely affects the vessel's sailing qualities. In addition, the dinghy can fill with sea water caused by large waves coming over the deck of the sailboat making the sailboat further stern heavy and possibly unseaworthy. Therefore, a preferable location for stowing a dinghy on a sailing vessel is at a forward location along the vessel's centerline so that: (i) the trim of the sailing vessel is not adversely affected; and (ii), the dinghy is forward of waves which typically impact the deck of the sailboat at an aft location. However, when stowing the dinghy forward along the vessel's centerline, problems are often encountered since such dinghies are difficult to manipulate as they are moved between a first location resting on the sailing vessel near the centerline, and a second location outboard of the deck edge, where they can be readily lowered into the water. Davits are unsuitable for accomplishing this type of operation.
Various conventional apparatus and methods have been disclosed for raising and lowering loads from a boat or ship. In U.S. Pat. No. 3,640,400--Becraft, there is disclosed a method for retrieving a submerged hose connected to a marker buoy to bring such hose aboard ship. The method utilizes a first cable to raise the marker buoy above the deck of the ship, and then a second cable to raise a section of chain attached to the marker buoy, in a manner such that the marker buoy is lowered onto the deck of the ship, and the first cable is then removed from the marker buoy and attached to another succeeding section of chain. The second cable lowers the first section of chain to the deck, then is removed from the first section of chain, and is reattached to a third section of chain to raise the third section above the deck. This process continues until the end of the chain attached to the submerged hose together with the submerged hose are retrieved.
An apparatus for engaging a torpedo floating in the water is disclosed in U.S. Pat. No. 3,262,585 by Olson, including a plurality of poles having cables which form open nooses which are threaded around the torpedo and then tightened around the outer surface thereof so that the torpedo can be manipulated in the water. The open nooses include a fixed loop for attaching a crane hook so that the torpedo can be hoisted out of the water and onto the deck of the ship. In U.S. Pat. No. 2,196,518 to Boudreau, a davit for hoisting a load to and from the deck of a boat is disclosed wherein the davit includes a carriage assembly mounted within a fore and aft track, and a first elongated member pivotally connected to the carriage for movement to an upright position to support a cable for hoisting the load, and a second elongated member pivotally connected to the carriage and having an end sleeve slidably engaged to the first elongated member for supporting the member in the upright position.
Snelling, U.S. Pat. No. 1,125,197 discloses apparatus for lifting boats from the well of a ship, including a boom for supporting cables which are attached to the boat and which are wound about a motor driven drum to raise and lower the boats from the well.
In Sawman, U.S. Pat. No. 1,094,750 a boat davit is disclosed including an elongated boom pivotally connected to upstanding flanges to support the boom between raised and lowered positions. The boat davit also includes an actuating arm threadably engaged to an elongated worm gear for longitudinal movement along the worm gear. The actuating arm is also pivotally connected to a base so that rotation of the worm gear by a crank causes the actuating arm to move longitudinally along the worm gear causing the boom to move between the lowered and raised positions.
U.S. Pat. No. 550,343--Greener, discloses a boom, slidably and rotatably connected to the mast of a sailing ship, and having a hook at an outboard end thereof for engaging a bridle supporting a lifeboat so that when the boom is lowered by block and tackle, the boat may be lowered over the side of the ship and into the water.